This disclosure relates generally to the field of wireless communication, and in particular to communication management in a network using uplink Spatial Division Multiple Access (SDMA).
Uplink SDMA (UL SDMA) is an advanced signal transmission technique used in wireless communication systems where multiple mobile stations (STAs) are allowed to communicate with an access point (AP) having multiple antenna elements sharing a same transmission time and frequency. The AP is configured to receive, via multiple spatially apart antenna elements, combined signals simultaneously transmitted from a plurality of STAs and separate the received signals into independent signals from each STA through appropriate signal processing. Also, the AP may transmit directional radio signals via multiple spatially apart antenna elements towards intended STAs to suppress interference and increase signal-to-noise ratio.
One of the standardized technologies that employs UL SDMA is the IEEE 802.16 for Wireless Metropolitan Area Network (WiMAX). In a WiMAX communications network, an AP combines a couple of STAs to create a SDMA group. The STAs belonging to a same group may transmit signals at a same time in a same frequency band using UL SDMA mechanism. Existing systems use polling procedures based on a TDMA MAC, resulting in inefficient polling procedures.